As the power of tractors and agricultural efficiency has increased, agricultural implements such as planters have increased in span, or width, to accommodate larger numbers of individual row units. Large planters generally include a main frame having a forward hitch assembly for drawing by a tractor and left and right wing sections pivotally attached to opposed lateral ends of the main frame. The pivoting wing connections allow the wings to fold relative to the main frame for transport and storage of the planter. Early planters pivotally displaced the wings vertically to reduce planter width and provide clearance for transport through narrow spaces. However, as the size of planters has increased, planter wings are generally folded in a forward direction to accommodate longer planter wings. This evolution has necessitated the incorporation of telescoping hitch assemblies to accommodate planter wings of increased length.
It is necessary to raise the planter frame on-the-go during operation in a field in order to elevate the row units above the soil. For example, at the end of a row of planted seed, dispensing of seed is interrupted temporarily while the tractor and planter combination typically executes a 180° turn to initiate planting of a follow-on row of seed, whereupon the row units are lowered on-the-go to the use position for again engaging the soil. It is also necessary to raise the planter unit and attachments for transport to provide adequate clearance between the row units and the roadway. It is desirable to have the same system and components control the height of the planter unit and its associated row units for field use as well as for transport and storage for design reasons as well as for increased efficiency and reduced cost.